This invention relates to an apparatus for crimping filamentary tow and more particularly to a loading arrangement for one of the forwarding rolls used to feed the tow into a stuffing box crimper.
It is well known in the art to crimp synthetic filaments that are to be processed either as broken tow or cut staple on textile processing equipment to yield yarns useful in the manufacture of fabrics. Without crimp, the tow or staple has low cohesiveness and cannot be drafted to uniform yarns on commercial textile equipment. One form of apparatus for crimping of filaments is the stuffing box crimper described in U.S. Pat. No. 2,747,233.
The crimping process usually is operated under conditions so critical that minor variations in the process can lead to crimper upsets which can result in severe product property variations such as unsatisfactory fiber properties and inadequate crimp.
A process variable that tends to give crimper upsets is the short term variations in crimper feed-rope denier resulting from merging of new ends with run-out tails of the old. Even if merges are staggered so that no two occur in parallel, the short-length increase in overall rope size can be sufficient, especially in high-speed processes, to initiate roll-clearance oscillations and out-of-control crimping during processing of several yards of rope. This problem was recognized by Stoveken and Talbott in their U.S. Pat. NO. 3,225,415, which teaches a sophisticated means to restore equilibrium operation following an upset.